Mechanical pencil



J. MEILNER MECHANICAL PENCIL Filed May 19,' 1936' Feb. 16, 1937.

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A RNY Patented Feb. 16, 1937 UNITED STATES PATENT OFFICE MECHANICAL PENCIL Joseph Meilner, West Orange, N. J.

Application May 19, 1936, Serial No. 80,500

5 Claims.

This invention relates in general to mechanical pencils of the type wherein the lead is projected and retracted from and into the casing by cooperation of a screw and slide, vone object of the invention being to provid-e such a pencil whichv shall be simple and inexpensive, reliable and durable in construction.

v `pencils of this general type usually include' a complete helix either in the form of a screw threaded tube' or a helical coil, and generally the screw threaded tube or helix serves to= hold and guide the lead or a separate tube is required for that purpose.

Another object of my invention is to provide a novel and improved construction and combination of a lead holding and guiding tube and mechanism cooperating therewith on the screw andslide principle whereby the necessityfor a complete helixon the tube shall be eliminated.

Another object isto` provide a novel and improved lead holding and guiding tube which may be formed of a single strip of Sheet metal rolled into the form of a tube and having knob-like protuberances stamped therefrom and spaced longitudinally thereof on the exterior to cooperate with a nut like element and a slide in the tube for projecting and retracting the lead from and into the casing etc., respectively; and to obtain other advantages and results as will be brought out by the following description.

Referring to the accompanying drawing in which corresponding and like parts are designated throughout Ythe several views by the same reference characters,

Figure lis a longitudinal sectional View through a mechanical pencil embodying my invention.

Figures 2 and 3 are transverse sectional views on the lines 2-2 and 33 respectively of Figure l.

Figure 4 is a view similar to Figure 1 showing a modification of the invention.

Figure 5 is a horizontal sectional view on the line 5-5 of Figure 4. 1

Figure 6 is a view similar to Figure 1 showing a further" modification of the invention.

Figure 7 is a horizontal Sectional view on the line 'I--'I of Figure 6.

Figure 8 is a fragmentary detached perspective view of the lead holding and guiding tube, and

' Figure 9 is a fragmentary sectional View showing a modication of the nut and propelling rod.

Specically describing the embodiment of the invention illustrated in Figures 1 to 3 inclusive the pencil includes a casing I which may conveniently be formed of a thin walled metal tube polygonal in cross section and having one end tapered at 2 from which the lead is to be projected.

Rotatablymounted in the casing I substantially coaxially therewith is a lead holding and guiding tube 3 which may be formed either of a (Cl. 1Z0-18) single sheet of metal rolled into tubular form with its edges in spaced relation to form a longitudinal slot between them parallel with the axis Aof the tube or be formed of a seamless tube having a longitudinal slot opening through one end. In Figure 1 the slot in the tube is designated 4. Preferably diametrically opposite the slot 4 rthe tube has stamped therefrom a plurality of knoblike protuberances 5 which are showny as equidistantly spaced in a straight row longitudinally of the tube to form in effect a straight rack. These protuberances may be formed in any suitable way. 'I'hey may conveniently be formed by the insertion of a tool or die through the slot 4 and pressing the metal outwardly from the inside `of the tube, or they may be formed before the sheet of metal of which the tube is formed, is rolled into tubular shape.

Within the tube is slidably mounted a lead propelling rod 6 which has at one end a lateral extension 'I projecting through the slot 4. The other end of the element 6 may have a socket 8 of any suitable known form to hold a lead 9. A pair of nuts I0 have internal threads of a pitch corresponding to the distance between the protuberances 5 and are mounted on the tube 3 in screw relation thereto and'at opposite sides of the projection 1 on the lead propelling element 6. 'I'he nuts are longitudinally slidable in the casing I but are held against rotation therein as by making the nuts of a shape corresponding to the polygonal cross section of the casi-ng.

The end of the casing I opposite the tapered end 2 has rotatably mounted therein a plug II which is xedly connected tothe tube 3. The plug II is shown as rotatably but longitudinally immovably connected to the casing by an internal rib I3 on the casing slidably seated in a groove vIII on the plug.

The end of the tube 3 opposite the cap I I projects frorn the tapered end of the casing and is slit at I5 so as to frictionally grip the lead 9.

With this construction upon relative rotation of the casing I and plug II,the nuts I0 will coact with the protuberances 5 with a screw action and will slide longitudinally of the casing so 'as to project or retract the lead, depending upon the direc-` tion of relative rotation of the casing and plug. After the lead has been projected it will be noted that the lead will be positively held in projected writing position even under heavy pressure on the projectd end, by engagement of the threads of the nuts with the protuberances 5.

Obviously the socket 8 in the propelling element 6 might be omitted in which case the propelling element would be moved in both directions but retraction of the -lead could be effected only by pressing inwardly on the projecting end thereof.'

Also it Will be Vunderstood that the protuber- @RCCS may be disposed otherwise than in a straight row as illustrated, Valthough that probably is the most satisfactory and economical manner of forming the protuberances.

A modification of the invention is shown in Figures 4 and 5 Where the casing IS is circular in cross section and has a tube l1 of polygonal cross section fixed therein to guide the nuts I8. This tube I1 may be formed of a single strip of metal folded upon itself, and may have projecting flanges I9 at its angles to space the tube from the inner walls of the casing I3 and provide reserve lead receivingpockets 20. The lead holding and guiding tube 2| and the propelling element 22 may be identical in construction with thatshown in Figure 1, while the nuts I8 may be the same as the nuts I3 except in size. Also the plug 23k may be connected tothe tube 2l in the same manner that the plug ll is connected to the tube 3. The operation of the pencil is other wise identical with that shown in Figure l.

In Figures 6 and 7 is shown another modification wherein Vthe casing 24 may be formed of molded plastic material and one end of the lead holdn ing and guiding tube 25 is fixed in a tip 26 which is connected to the casing by a sleeve 21 having a keyed or feather and spline connection with the easing and rotatably mounted on the tube 25 between the tipand a collar 28 iixed on the tube. With this construction, the casing and tip 26 may have relative rotation and the tube 25 will rotate with the tip. At the end of the casing opposite the tip is fitted a cap 29 which may be secured to the casing by lan inturned ange 30 on the cap seated in an exterior groove 3l on the casing.

For actuating the lead propelling element 32, I have shown a sleeve 33 having secured therein a helical coil 34 which has a screw thread relation to the protuberances on the lead holding and guiding tube.

The sleeve is longitudinally slidable in the casing but held against longitudinal movement as by a keyed relation or by making the interior of the casing and the exterior of the sleeve of corresponding polygonal cross section as shown in Figure '1. Relative rotation of the tip 26 and casing in opposite directions will slide the sleeve 33 in opposite directions, but the lea-d will be propelled by the propelling element 32 in only the direction to project the lead. The lead will be retracted by retracting the sleeve 33 and then manually pushing the lead inwardly of the cas- In Figure 9, I have shown a further modification wherein the propelling rod is actuated in both directions by the nut. Here nut 35 has beveled edges at its ends 36 and the propelling rod 31 extends through the nut and has lateral extensions or arms 38 and 39 projecting through the slot in the lead holding and guiding tube and turned inwardly over the respective beveled edges of the nut to connect the propelling rod to the nut but permit free rotation of the nut under the arms. The propelling rod and the nut can be handled together as a unit and thereby facilitate assembly and reduce the possibility of loss of either. The rod and nut may be assembled by forming the rod with the end arm 33 projecting in alinement with the rod, slipping the nut on the rod against the arm 38 and then bending the arm 39 inwardly over the corresponding beveled end of the nut.

In use, the nut and rod may be used in conjunction with a lead holding and guiding tube 40 and casing 4l in the same manner, for example as shown in Figures 1, 4 and 6, and upon relative rotation of the lead holding tube and nut in opposite .directions the rod 31 will be reciprocated in both directions.

Where the lead holding tube is formed of a single sheet of metal rolled upon itself or the slot extends throughout the length of the tube, a stop to limit outward movement of the propelling element may be formed as by the collar 28, or if desired, such a stop may be provided by the end of the slot, as at 350, where the tube is seamless and the slot does not extend throughout the length of the tube.

Other modications in the details of structure of the pencil will occur to those skilled in the art as within the scope of the invention. The essence of the invention is the lead holding and guiding tube having the spaced protuberances 5 to cooperate with a nut-like element and a lead propelling element.

Having thus described my invention, what I claim is:

1. As a manufacturing unit for mechanical pencils, a lead holding and guiding tube having a longitudinal slot and a plurality of exterior knoblike protuberances stamped integrally from the walls of the tube and spaced equidistantly longitudinally thereof in a row.

2. As a manufacturing unit for mechanical pencils, a lead holding and guiding tube comprising a sheet of metal rolled upon itself with its edges in spaced relation and parallel with the axis of the tube, and a plurality of exterior knob-like protuberances stamped Yintegrally from the sheet spaced equidistantly longitudinally of said tube in a straight row diametrically opposite the space between said edges.

3. As a manufacturing unit for mechanical pencils, a lead holding and guiding tube having a longitudinal slot parallel with the 'axis of the tube, and a plurality of exterior knob-like protuberances stamped integrally from the walls of the tube and spaced longitudinally of said tube in a straight row diametrically opposite said slot.

4. A mechanical pencil including a casing, a sheet metal lead holding and guiding tube rotatable but longitudinally immovable therein and having a longitudinal slot, and a plurality of knoblike exterior protuberances stamped integrally from the walls of the tube and spaced equidis- Vtantly longitudinally of the tube in a row, a lead propelling element slidable in said tube and having a projection slidable in and extending through said slot, and a nut-like element slidable longitudinally of but non-rotatable in said casing and rotatable on said tube to cooperate with said protuberances with a screw Vaction and move longitudinally of the tube, said nut-like element having an operative engagement with said projection on said propelling element to slide the latter JOSEPH MEILNER. 

